Plumb GpuSwapBuffers completion from Mus GPU thread to WS thread

components/mus/gles2/gl_surface_adapter.cc

Index: components/mus/gles2/gl_surface_adapter.cc
diff --git a/components/mus/gles2/gl_surface_adapter.cc b/components/mus/gles2/gl_surface_adapter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..827028821b29e329792cdf3c31b5f01827857521
--- /dev/null
+++ b/components/mus/gles2/gl_surface_adapter.cc
@@ -0,0 +1,57 @@
+// Copyright (c) 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/mus/gles2/gl_surface_adapter.h"
+
+#include "base/bind.h"
+
+namespace mus {
+
+GLSurfaceAdapterMus::GLSurfaceAdapterMus(scoped_refptr<gfx::GLSurface> surface)
+    : gfx::GLSurfaceAdapter(surface.get()),
+      surface_(surface),
+      weak_ptr_factory_(this) {}
+
+GLSurfaceAdapterMus::~GLSurfaceAdapterMus() {}
+
+void GLSurfaceAdapterMus::SwapBuffersAsync(
+    const GLSurface::SwapCompletionCallback& callback) {
+  gfx::GLSurfaceAdapter::SwapBuffersAsync(
+      base::Bind(&GLSurfaceAdapterMus::WrappedCallbackForSwapBuffersAsync,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void GLSurfaceAdapterMus::PostSubBufferAsync(
+    int x,
+    int y,
+    int width,
+    int height,
+    const GLSurface::SwapCompletionCallback& callback) {
+  gfx::GLSurfaceAdapter::PostSubBufferAsync(
+      x, y, width, height,
+      base::Bind(&GLSurfaceAdapterMus::WrappedCallbackForSwapBuffersAsync,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void GLSurfaceAdapterMus::CommitOverlayPlanesAsync(
+    const GLSurface::SwapCompletionCallback& callback) {
+  gfx::GLSurfaceAdapter::CommitOverlayPlanesAsync(
+      base::Bind(&GLSurfaceAdapterMus::WrappedCallbackForSwapBuffersAsync,
+                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void GLSurfaceAdapterMus::WrappedCallbackForSwapBuffersAsync(
+    const gfx::GLSurface::SwapCompletionCallback& original_callback,
+    gfx::SwapResult result) {
+  if (!adapter_callback_.is_null())
+    adapter_callback_.Run(result);
+  original_callback.Run(result);
+}
+
+void GLSurfaceAdapterMus::SetGpuCompletedSwapBuffersCallback(
+    gfx::GLSurface::SwapCompletionCallback callback) {
+  adapter_callback_ = std::move(callback);
+}
+
+}  // namespace mus